Understanding Heat, Air, and Moisture Control The gaps between design and performance by Sarah K. Flock, CDT, AIA and Carole Ceja, NCARB, RRC Photo © Bigstock.com MANY DESIGNERS AND SPECIFIERS UNDERSTAND CONTROLLING AIR, VAPOR, AND THERMAL TRANSFER HELPS MITIGATE MOISTURE PROBLEMS WITHIN THE BUILDING ENVELOPE. MOISTURE ACCUMULATION IS A PERFORMANCE ADVERSARY THAT CAN LEAD TO STRUCTURAL DETERIORATION, FINISH DAMAGE, ORGANIC GROWTH, AND REDUCED BUILDING LONGEVITY (FIGURE 1). HOWEVER, NAVIGATING FUNDAMENTALS, CODE REQUIREMENTS, AND INDUSTRY TRENDS RELATED TO THESE TRANSFER MECHANISMS CAN BE COMPLEX. 30 the construction specifier | may 2016 CS_May_16.indd 30 The 2015 International Codes (I-Codes) were recently released; as of this writing, six states have adopted the 2015 International Energy Conservation Code (IECC) and International Building Code (IBC), with many more expected to join in the months to come. Even when designs meeting current codes are achieved, moisture issues can result. This article explores the impact of recent code changes, highlights various provisions’ potential limitations, and presents examples of ‘gaps’ between codes and real-world performance as they relate to the topics of air, vapor, and thermal control. www.constructionspecifier.com 2016-04-18 12:13 PM